Control valve system for pneumatichydraulic tools



FIG. I.

y 24, 1962 c. E. WEBBER ETAL 3,045,433

CONTROL VALVE SYSTEM FOR PNEUMATIC-HYDRAULIC TOOLS Filed April 15, 1960 2 Sheets-Sheet 1 .3 "3' 3 0 3% 3 '0 g) g O l m l 0 N l N '0 k 5 w l i Q) i 1 a 1 3 I m k I I W l\ i x 5 Clarence E Web Der F W/IIard 6. 77/952 n INVENTORS & 1-3

TTORNE Y Jul 24, 1962 Filed April 15, 1960 c. E. WEBBER ETAL 3,045,433

CONTROL VALVE SYSTEM FOR PNEUMATIC-HYDRAULIC TOOLS 2 Sheets-Sheet 2 FIG. 4.

V 9 Clarence E Webber Willard G. Tr/esf INVENTORS wy-1M TORNE Y nit ed States land Filed Apr. 15, 1960, Scr. No. 22,462 9 Claims. (Cl. 60-545) This invention relates generally to pilot operated valves, and more particularly it pertains to a finger triggered directional valve for a pneumo-hydraulic type actuator.

In Letters Patent No. 3,002,548, of Don J. Marshall, entitled Tire Removing Tool issued October 3, 1961, there has been described a wheelwrights tool which requires the application of air pressure selectively to one of a pair of cylinders and the venting to atmosphere of the other.

It is the object of the present invention to provide a compact, finger triggered, pilot operated valve which is conveniently associated with a handle for supporting and controlling an actuator tool from airpressure:

Another object of this invention is to provide a compact self-neutralizing directional control valve having a minimum of parts which is easy and economical to manufacture and which can readily be disassembled for cleaning.

And still another object of this invention is to provide a unique self-neutralizing directionalcontrol valve for use i atent full of hydraulic fluid (not shown).

a nipple 20, as shown best in FIGS. 1 and 3, thereby driving a piston 22 downwardly, or to the right when viewed in FIG. 1.

The piston 22 drives its hollow piston rod 24 into a cylinder 26. Piston rod 24 and cylinder 26 are always As the piston rod 24 is forced into the cylinder 26, the fluid contained within the piston rod 24 and cylinder 26 is forced through a passage 30 into a slave cylinder 32, thereby driving a slave piston 34 and its associated piston 'rod 36 and dog 38 outwardly or to the right as best illustrated in FIG. 1.

with a wheelwrights tool which is eificient and reliable in operational use.

To provide a new type and design of a directional control valve is still another object of this invention. 7

These and other objectsand. advantages of this invention will become more readily apparent from the following detailed specification and accompanying drawings in which:

FIG. 1 is a generally schematic longitudinal section through a pneumatic-hydraulic tire removing tool incorporatingthe control valve of the present invention;

FIG. 2 is an end elevation, on an enlarged'scale, of the tire removing tool and control valve as viewed from th left of FIG. 1;

FIG. 3 is a cross-section taken on line 33 of FIG. 1 with most of the elements appearing in elevation;

FIG. 4 is across-section, on a further enlarged scale, through the control valve and is taken on line 4-4 of FIG. 3;

FIG. 5 is a cross-section taken on line -5--5 of'FIG. 4;

FIG. 6 is a cross-section taken along line 6-6 of FIG. 4with most of the elementsappearing in elevation; and

FIG. 7 is a cross-section taken along line 77 of FIG. 5.

It is believed that the construction and functions of the instant invention will be more readily appreciated after a short discussion of a pneumatic-hydraulic tool of the type to whichthe valve would be applied.

Referring now to FIG. 1 of the drawings, there is shown generally by reference numeral -10 a control valve which consists of a valve head assembly 12 and a base assembly 14, secured to a tire removing tool 16.

The tire removing tool 16 is illustrated in an Off condition. Inother words, a dog 38, which is used to break a tire bead away from a wheel rim, is shown in itsfully retracted position,

The dog 38 is driven forward or extended as will now be explained. Compressed air is fed to the valve 10 through an airline 48 through a nipple 50, shown best in FIGS. 2 and 3. After passing through the various passages within the valve, as will be fully described sub sequently, the air isfed into a master cylinder 18 through The air contained within the cylinder 18 and surrounding the hollow piston rod 24 is expelled through a bleed fitting 28 as the piston 22 moves to the right. The air contained Within the slave cylinder 32 is driven through a passage 40 and through a fitting 42 into a tube 44 which lies beneath a cover plate 46. Tube 44 directs the air back through the valve 10 where it is exhausted to atmosphere.

When it is desired to retract the dog 38, that is, restore it to the position illustrated in FIG. 1, the above described procedure is reversed.

Compressed air is directed by valve 10 into the slave cylinder 22 through tube 44, fitting 42, and passage 40 thus driving the slave piston 34 to the left. The fluid contained within cylinder 32 to the left of piston 34 is forced through passage 30 into cylinder 26 and the hollow piston rod 24, thereby driving the piston 22 to the left. The air to the left of the piston 22 is directed through the nipple 20 into the valv 10 where it is exhausted to atmosphere. As the piston 22 moves to the left, the air which it displaces on its left is replaced on its right by bleed 28.

. It now becomes clear from the preceding discussion that the.primary function of valve 10 is to selectively supply compressed air either to the master cylinder 18 through the nipple 20, thereby extending dog 38, or to the slave cylinder 32 through tube 44, thereby withdrawing the dog 38.

As best illustrated in FIG. 4, air is selectively directed into the nipple 20 to extend the dog 38, or into tube 44, to retract the dog 38, by. means of a sliding spool 96 whichis arranged with a central land 98 and end lands 100 and 102.

FIG. 4 illustrates the spool 96 in its extreme left position, in which position compressed air would be directed into tube 44 to retract the dog 38. To extend dog 38,

the spool 96 would be moved to'the extreme right, whereby air would be directed into the nipple 20. When the tool 16 is at rest, the spool 96 is automatically returned to' a mid-position. The method of actuating the spool 96 will be described in detail subsequently.

Air is directed through the. valve 10 to the nipple 20 or the tube 44 as will now be described. Compressed air enters the valve base 14 through the previously mentioned line 48and the nipple 50 and passes through a passage 52 into a narrow chamber 54 and then into a chamber 104 in the head assembly 12. When tool 16 is at rest, the

central land 98 of spool 96 will overlie the chamber 104,

thus preventing further movement of air.

A gasket 124 is provided to prevent air leakage between the valve head 12 and base 14. The spool 96 is contained within a plurality of sleeves which reside within a bore 78 which runs through the valve head 12. The ends of bore 78 are closed by caps 84 which are secured in place by retaining rings 88. The sleeves 80 are arranged with apertures 82 which are aligned with various cham bcrs 104, 106, 112, 116 and 120. The alignment of the apertures 82 with the various chambers is maintained by a plurality of 0 rings 94.

Now, when the spool 96 is moved to the left as shown in FIG. 4, compressed air from chamber 104 will enter 2% the space between the lands 98 and 102 and pass into the chambers 106 and chamber 108 in the base 12. From chamber 108, the air will enter passage 110 by which it will be directed into tube 44, thus retracting cylinder 34, piston rod 36, and dog 3.8.

The air which was contained above, or to the left of the master piston 22 when viewing FIG. 1, will be forced through nipple 20 into the chamber 114 in base 14 and then into the chamber 112 in valve head 12. The exhausting air then passes between lands 98 and 100 to enter the chamber 116 from where it escapes to atmosphere through an exhaust port 118.

When the spool 96 is moved to the full right position, opposite that shown in FIG. 4, land 100 will close off the exhaust chamber 116, and the groove between lands 98 and 100 will permit passage of the air between chambers 104 and 112, While the groove between lands 98 and 102 will permit passage of the air from chamber 106 to chamber 120.

With the spool 96 in the full right position, compressed air passes from line 48 into passage 52, chamber 54 and chamber 104. The groove between lands 98 and 100 now couples the chamber 112 to the chamber 104, thereby permitting air to enter a chamber 114 from which it passes into the master cylinder 18 through the nipple 20.

The exhaust air from slave cylinder 32 enters the base 14 through the tube 44 and passes through the passage 110 into chamber 108 and into chamber 106. The groove between lands 98 and 102 now couples chamber 106 to chamber 120, and allows air to pass from chamber 106 through chamber 120 into an exhaust port 122 where it escapes to atmosphere.

The previously described spool 96, which governs the supply of air either to the master cylinder 18 or slave cylinder 32, is maintained, when neither cylinder 18 or 32 is being fed, in a position midway of its extreme left or right movement.

The spool 96 is held in this midway or balanced position by exposing both of its ends to air which is leaked from the main air supply as will now be discussed. Chamber 54, which is constantly pressurized, communicates with a short cross-slot 56, as 'best illustrated in FIG. 3. The ends of slot 56 are provided with small diameter passages or bleeds 58, each of which enters one of a pair of cavities 60.

Referring now to FIGS. 3, 5, 6 and 7 of the drawings, it will be seen that compressed air which leaks into slot 56 from the chamber 54 passes through the diverging bleeds 58 into the cavities 60.

The air in the left cavity 60 passes through a doglegged" groove 70 to a short vertical passage 74 which opens at its upper end into an annular space 90 surrounding the left hand end cap 84. Similarly, the air in the right hand cavity 60 passes through a dog-legged groove 72 to a short vertical passage 76 which opens at its upper end into an annular space 92 surrounding the right hand end cap 84.

Both end caps 84 contain apertures 86 which receive air from annular grooves 90 and 92. It should be noted that the aperture 86 in the left hand end cap 84 is obscured in FIG. 4 by the land 100. However, the inside diameter of the end caps is sufiiciently greater than the diameter of the lands 100 and 102 so as to permit free flow of air to both ends of the spool 96, thereby balancing the spool in a mean position. Leakage of air from within the end caps 84 is insured against by the rings 94 which lie adjacent the inner faces of the end caps.

Referring back especially to FIG. 7, there is noted a pair of commercially available valves 62 and 64. These valves are a somewhat modified variety of common hollow automotive tire valves and it is not considered necessary to detail their construction.

The two valves 62 and 64 are firmly press fitted into a pair of apertures in the valve head. These apertures overlie the cavities 60 which freely receive and surround the lower ends of valves 62 and 64. Centered between the valves 62 and 64, there is provided a valve actuator 66 which rotates on a pivot screw 68.

It will be noted that when the actuator 66 is rotated a very short distance counterclockwise, the stern of valve 62 will be engaged thereby opening the valve and allowing the air entering the left cavity 60 to dump to atmosphere.

At the same time, air entering the right hand cavity 60, will continue through groove 72, passage 76, and annular space 92 to enter the right hand end cap 84, thereby driving the spool 96 to the left.

When the actuator 66 is released, valve 62 will close, thereby allowing the air to enter both end caps 84, thus causing the spool to center itself. By rotating the actuator 66 clockwise, valve 64 is opened causing the air to be fed only to the left end of spool 96 and driving the spool to the right.

For convenience in use the valve head 12 is formed integrally with a handle 130. It should be noted that the valve head 12 and base 14 are secured together by bolts 126 and then the entire assembly is attached to cylinder 18 by studs 128 which are welded to the cylinder 18.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In combination with a pneumatic-hydraulic actuator assembly for actuating a tool having a pneumatic cylinder arrangement, a master hydraulic cylinder arrangement, and a slave cylinder arrangement, each said cylinder arrangements being provided with a cylinder and a piston, a piston rod integrally connecting together the pistons of said pneumatic and master cylinder arrange- 1 ments, said slave cylinder arrangement being provided with a piston rod connecting the piston of said slave cylinder arrangement with said tool to be extended and retracted, the chamber of the master cylinder on the piston rod side of said master cylinder arrangement having a hydraulic medium therein, the chamber of said master cylinder arrangement being arranged to communicate by dra'ulically with the chamber of the slave cylinder arrangement located on the opposite side of the piston rod of said slave cylinder arrangement, and a finger triggered, self-neutralizing pneumatically shifted directional control valve means connected to the chamber of said pneumatic cylinder arrangement and to the piston rod side of said slave cylinder arrangement for selectively introducing a pressurized medium into the chamberof said pneumatic cylinder arrangement as well as to the piston rod side of said slave cylinder arrangement to extend said tool as well as to retract said tool, respectively.

2. In the combination as recited in claim 1, wherein the diameter of said piston for said pneumatic cylinder arrangement is of greater diameter than the diameter of said pistons for said master and slave cylinder arrangements so that the relative sizes of said pistons effects a multiplication of force applied to said tool.

3. In the combination as recited in claim 2, wherein said slave cylinder arrangement is laterally spaced from said master cylinder arrangement.

4. In the combination as recited in claim 1, and means for restricting the fiow of fluid to said chamber of said slave cylinder on the opposite side of the piston rod of said slave cylinder arrangement.

5. In a pneumatic-hydraulic actuator assembly for actuating a tool having a pneumatic cylinder arrangement, a master hydraulic cylinder arrangement, and a slave cylinder arrangement, each said cylinder arrangements being provided with a cylinder and a piston, a piston rod integrally connecting together the pistons of said pneumatic and master cylinder arrangements, said slave cylinder arrangement being provided with a piston rod connecting the piston of said slave cylinder arrangement with said tool to be extended and retracted, the chamber of the master cylinder on the piston rod side of said master cylinder arrangement having a hydraulic medium therein, the chamber of said master cylinder arrangement being arranged to communicate hydraulically with the chamber of the slave cylinder arrangement located on the opposite side of the piston rod of said slave cylinder arrangement; and a'pneumatically shifted, self-neutralizing directional control valve means connected to the chamber of said pneumatic cylinder arrangement and to the piston rod side of said slave cylinder arrangement for selectively introducing a pneumatic medium into the chamber of said pneumatic cylinder arrangement as Well as to the piston rod side of said slave cylinder arrangement to selectively extend as Well as to retract said tool, respectively.

6. In an actuator assembly for actuating a tool having a first cylinder arrangement, a second cylinder arrangement, and a third cylinder arrangement, each said cylinder arrangements being provided with a cylinder and a piston, a piston rod integrally connecting together the pistons of said first and second cylinder arrangements, said third cylinder arrangement being provided with a piston rod connecting the piston of said third cylinder arrangement with said tool to be extended and retracted, the chamber of the second cylinder on the piston rod side of said second cylinder arrangement having an incompressible medium therein, the chamber of said second cylinder arrangement being arranged to communicate with the chamber of said third cylinder arrangement located on the opposite side of the piston rod of said third cylinder arrangement, and a self-neutralizing pneumatically shifted directional control valve means connected to the chamber of said first cylinder arrangement and to the piston rod side of said third cylinder arrangement for se lectively introducing a pressurized medium into the chamber of said first cylinder arrangement as well as to the piston rod side of said third cylinder arrangement to selectively extend as well as to retract said tool, respectively.

7. In the actuator assembly for actuating said tool as recited in claim 6, wherein the diameter of said piston for said first cylinder arrangement is of greater diameter than the diameter of said pistons for said second and third cylinder arrangements so that the relative sizes of said pistons effects a multiplication of force applied to said tool.

8. In the actuator assembly for actuating said tool as recited in claim 2, wherein said third cylinder arrangement is laterally spaced from said second cylinder arrangement,

9. In the actuator assembly for actuating said tool as recited in claim 6, and means for restricting the flow of fluid to said chamber of said slave cylinder on the opposite side of the piston rod of said slave cylinder arrangement.

References Cited in the file of this patent UNITED STATES PATENTS 733,497 Mar-tin July 14, 1903 2,526,956 Kugler Oct. 24, 1950 2,536,709 Ashton et al. Jan. 2, 1951 

